Electric fuse box



ELECTRIC FUSE BOX Filed Aug. 7, 1944 lzl I :2

Way 1.

Patented Aug. 17, 1948 UNITED STATES PATENT OFFICE ELECTRIC FUSE BOX Romain Bauwens, Burton, Wash.

Application August '1 1944, Serial No. 548,443

1 Claims. (01. 200-114) This invention relates to a fuse or entry box for use in electric-wire hook-ups, and to the fuses employed therewith, and has for its principal object the provision of advanced box structure assuring maximum ease in wiring and which, without necessitating a cutting of the master switch, permits ruptured fuses to be readily replaced with assurance of complete safety against possibility of electric shock. It is a further and important object to provide a fuse box of a nature substantially precluding the employment of pennies or other make-shift conductive agencies as a circuit-closing instrumentality. As a still fur-- ther object, the invention aims to provide a new and advanced fuse'of the type permitting replacement of the fusible element only and which, by reason of its structural simplicity directly resorting to the use of contact prongs as a means of clamping the link in its circuit-completing position, permits the fuse to be produced at a cost below replaceable-link fuses heretofore devised.

Other objects and advantages will, with the foregoing, appear and be understood in the course of the following description and claims, the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawing:

Figure 1 is an elevational view illustrating a fuse box, with fuses applied, produced in accordance with the present invention. The cover for the box is deleted to permit a full-line showing of the several fuses.

Fig. 2 is a horizontal sectional view taken on jogged line 2-2 of Fig. 1.

Fig. 3 is a sectional view detailing one of the branch circuit fuses employed in the box; and Fig. 4 is a top plan view thereof.

Fig. 5 is an underside plan view showing a main fuse, the characterizing feature thereof being an ability to renew the fusible link.

Fig. 6 is a. disassembled view portraying one of the removable contact prongs of the main fuse, and the thimble-piece which serves as a socket therefor when applying the prong to the fuse body, the prong being illustrated in elevation and the thimble-piece in section; and

Fig. 7 is an elevational view of the metal clip which is enclosed within the fuse block of the entry box and constitutes a mating complement of the contact prong, dotted lines being employed to indicate the said prong and which is shown in its engaged position.

As is customary, the invention employs the usual cabinet comprising a bottom member and a hinged cover therefor, designated by the numerals l0 and H respectively, arranged to be firmly secured upon a sustaining wall and admitting to the insertion, through knockouts or the like (not shown), of the several lead-in wires H of various main and branch circuits to which the box is applied as protection against overloads.

The fuse-block of the invention is received within this bottom member to occupy a position spaced a sufficient distance above the base wall thereof as to describe a fairly deep compartment l3 below the block, and in supporting the block to give ready access to its underside the same is given a hinge mounting. as at I, a cap screw l'5 being applied to the free end of the block for anchoring the latter in the normal operating position.

There are employed, to form said fuse-block, two plates l6-l'| produced, desirably, to a rectangular plan configuration from any suitable insulating material as, for example, Bakelite, fibreboard, or the like, and detachably secured in contiguous relation by nutted bolts i8. Recessed into the meeting faces of the plates are registering cavities |9-20 describing a severalty of separated and ostensibly closed cells, and introduced to each said cell is a standard U-clip-of comparatively heavy-gauge metal-0f the type commonly employed in the electrical appliance field as a receiving socket for a contact prong. These clips are fixedly carried upon the head ends of binding posts 2| received through openings 22 bored in the lower plate I6 and projecting by their other ends into the compartment l3, being therein fitted with the usual complement of nuts 23 serving to bind the terminal ends of related circuit wires and, by clamping engagement against the lower face of the plate, giving rigidity to the clips. The referred-to prongs, and which will be hereinafter more particularly described in course of setting forth the structural nature of the fuses, find engagement with the clips through openings 25 bored through the upper plate ll.

Said clips, to accommodate the two wires of a single main or a single branch electric circuit, as the case may be, are in pairs placed according to a desired pattern and are distinguished, the main from the branch circuit clips, by 21 and 26, respectively, and it will be seen that I have elected to illustrate a fuse-block providing the required clips for accommodating five branch and two main circuits. The distributional arrangement is of no moment to the invention but it becomes desirable to group the branch circuit clips at one longations.

poleslmay be readily gripped by pliers to effecend and the main circuit clips at the other end of the block.

Proceeding to describe the fuses, with reference being first had to the fuse for a respective said minor or branch circuit, there is provided a body 30 desirably molded from a thermoplastic material of insulating nature and having embedded therein a pair of metal prongs 3i--32 placed in parallelism and spaced apart a distance corresponding to the spacing between two of the openlugs 25 leading to a related set of clips, the lower ends of such prongs projecting as contact poles and the upper ends extending into a chamber 33 formed in the upper side of the body. There is formed upon the embedded shanks of the prongs a shoulder-producing flange 34 which looks the prongs again-st axial movement, and exposed within the chamber and lying somewhat below the upper extreme end is a similar flange 35. 36 denotes the fusible link, formed to fit by its ends over the upper ends of the prongs in spanning relation to the latter, and which is made fast by the instrumentality of swaging the stud tips of the prongs. A sheet 31 of mica or equivalent material is applied as a closure for the chamber.

Considering the main-circuit clips, the fuses therefor are of a somewhat different construction primarily distinguished by an ability to renew the fusible links following an overloading rupture, and there is employed therefor a body 40 similarly molded from a suitable thermoplastic but formed to present an open chamber upon the underside and. in lieu of embedding the prongs, as 4| and 42, within the material of the body, molding internally-threaded thimbles 43 within the latter. Said thimbles, locked in relation to the body by the'counterpart 44 of the flange 34, are spaced in correspondence with-the spacing which obtains between related openings leading to a set of the main clips 21, and have their threaded sockets exposed for the reception therein of mating studs 45 produced as integral prolongations of the said prongs. Designated by 48, the renewable link has its ends apertured I to register with the thimble sockets, and is gripped against the faces of the thimbles by a flange 50 produced at the midlength of the prongs to occup a position in intervening relation betweeen the contact poles and the threaded pro- The smooth surfaces of the contact tuate the necessary clamping pressure to firmly engage the fusible link, or the operation might, if desired, be performed by the use of a wrench and which,wou1d be accommodated by facing down opposite sides of the said flange.

- The structural nature of the box, its fuse-block, and the fuses for the latter will be readily understood from the foregoing description taken in connection with the illustration of the invention. Both the base wall of the branch-circuit fuses and the basal rim of the skirt which carries about the perimeter of the main fuses fit flush with the exposed face of the block upon application to the latter, and it will be seen that a finger-engaging notch Si is formed in the end walls of the fuse bodies in facilitating removal either to bodily replace a branch-circuit fuse or to renew the ruptured link of a main fuse. Wiring of the block is easily accomplished by withdrawing screw l and swinging the block outwardly upon its hinges, giving ready access to the underside. All circuit wires as well as electrically conductive parts brought into the circuit are completely isolated upon the return of the block to operating normalcy, thus rendering the box completely fool-proof from the standpoint of' receiving an accidental shock in course of either removing a fuse from or applying same to the block while the master switch is closed.

It is my intention that no limitations be im lied either from the foregoing description or the illustration to whichv the same refers, as I consider all forms of construction and variation in detail coming within the scope of the hereto an- I and bottom walls of the casing, said compartment and the underside of the block being exposed for servicing by the act of swinging said block from its said housed position, said block comprising complementary close-fitting plates of insulating material detachably secured one in overlying relation to the other and having the meeting faces cavitated to. provide separated internal cells arranged in sets of two, said plates having openings bored from the outer faces thereof to the respective cells; binding posts having conductive U-clips anchored to the head ends of the same and received through said lower-plate openings to locate the U-clips within the cellsand project the lower ends below the block; binding nuts for said projecting ends of the posts; electrically-conductive prongs for respective said U-clips arranged to be inserted through the upper-plate openin s into socketing engagement with the clips; fuse bodies fixedly supporting a pair of said prongs and holding the latter to a fixed spacing correspondingto that of the upper-plate openings for a given set of clips; and links, fusible under a given current overload, encased by respective fuse bodies and applied as a spanning connection between the two prongs.

2. As a fuse assembly, in combination: an electric fuse-block comprised of complementary close-fitting plates of insulating material detachably secured one in overlying relation to the other and formed in their meeting faces with registering cavities describing internal cells separated, one cell from another, and arranged in sets of two, said plates having openings bored from the outer faces thereof to connect with the respective cells and said fuse-block being other wise closed against access to the internal cells;

binding posts carrying fixed U-clips upon their head ends and received through said lower-plate openings to have the u-clips lie within the cells and the lower ends project below the block; binding nuts for said projecting ends of the posts; conductive prongs functional to the clips and arranged to be inserted through the upper-plate openings into socketing engagement within the throat described by a respective said clip; fuse bodies acting to respectively support a pair of said prongs and hold the latter to a fixed spacing corresponding to the spacing which obtains between the openings of the upper plate related to a given set of clips; and links, fusible under ductive U-clips substantially encased within the block to locate the throat of the U uppermost and separated one from another in sets of two, said block having openings bored from the upper face and registering with the throat of a respective said clip; means for attaching the two wires of a severalty of electric circuits one to one and the other to the other U clip of a respective said set; conductive prongs functional to the clips and arranged to be inserted through said openings into socketed engagement within the throats of the clips; bodies of insulating material each supporting a pair of said prongs and holding the latter to a fixed spacing corresponding to that of the openings related to given sets of clips; and links, fusible under a given current overload, encased by respective fuse bodies and applied as a spanning connection between the two prongs, said prongs being removably associated with the supporting bodies therefor and each providing a flange placed central to the length of the prong, and said links being renewable and being directly gripped by the flanges of the prongs for securing the links as a spanning connection between the prongs.

5. As a renewable electric fuse: a fuse body of insulating material formed upon its underside with an open chamber marginally described by a skirting wall, and having a pair of internally threaded thimbles fixedly embedded within the head part of the body to lie in separated relation with the threaded sockets exposed to the roof of the chamber; a conductive prong for each said thimble provided upon one end with a threaded stud functional to the threads of the thimble as a mating complement therefor and upon the other end presenting a contact pole extending as an axial prolongation of the stud and arranged and adapted. by socketing of the studs, to project below the lower rim of said skirting wall; and a link, fusible under a given current overload, arranged to extend as a spanning connection from one to the other said prong and apertured to register by its two ends with the sockets of the thimbles, the prongs present ing shoulders at the juncture of pole and stud acting by the threading engagement of the stud to clamp the fusible link against the face of the thimble.

6. As a renewable electric fuse, in combination" with a pair of internally threaded thimbles, and a supporting body therefore fixedly securing said thimbles to have the same lie in spaced parallel relation with the threaded sockets exposed: a renewable conductive link, fusible under a given current overload, arranged to span the two thimbles and apertured by its ends to register with the exposed sockets of the latter; and contact prongs finding detachable engagement within the sockets of the thimbles and bearing directly upon the fusible link to clamp the latter.

7. The fuse assembly of claim 4 in which the end of a respective said prong lying at one side of said flange is threaded; and an internally threaded thimble for each said prong embedded within the material of the supporting body to accommodate the removable reception of said threaded end; i

.. ROMAIN BAUWENS.

REFERENCES orrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,482,958 Ullrich Feb. 5, 1924 FOREIGN PATENTS Number Country Date 21,678 Great Britain Nov. 29, 1900 2,131 France Nov. '7, 1903 (Addition to N0. 311,048) 

